Rotary paper cutter with spring strap drive

ABSTRACT

A paper cutter of the type having a rotary blade movable adjacent to and along one side margin of a board for supporting paper wherein the blade is coupled to one of a pair of adjacent rollers carried by a channel member disposed longitudinally of the side margin of the board. A resilient strap is secured at its ends to the ends of the channel member and is partially wrapped around the rollers to cause rotation of the same while permitting movement of the rollers and thereby the cutter blade with minimum resistance due to friction. Means is provided to bias the cutter blade toward the side margin.

United States Patent Lind [54] ROTARY PAPER CUTTER WITH SPRING STRAP DRIVE [72] Inventor: Jack 0. Lind, 2704 Fairbrook Drive,

Mountain View, Calif. 94040 [22] Filed: Dec. 5, 1969 211 Appl. No.: 882,573

2,219,485 10/1940 Neuwirth 2,765,037 10/1956 McDonoughetal. ..83/489 5] Mar. 14, 1972 FOREIGN PATENTS OR APPLICATIONS 689,422 3/1953 Great Britain ..83/489 Primary Examiner-William S. Lawson Attorney-Townsend and Townsend [5 7] ABSTRACT A paper cutter of the type having a rotary blade movable adjacent to and along one side margin of a board for supporting paper wherein the blade is coupled to one of a pair of adjacent rollers carried by a channel member disposed longitudinally of the side margin of the board. A resilient strap is secured at its ends to the ends of the channel member and is partially wrapped around the rollers to cause rotation of the same while permitting movement of the rollers and thereby the cutter blade with minimum resistance due to friction. Means is provided to bias the cutter blade toward the side margin.

9 Claims, 4 Drawing Figures PMWEHMAR m I972 INVENTOR JACK 0..-L|ND BY WWW ATTORNEYS ROTARY PAPER CUTTER WITH SPRING STRAP DRIIVE This invention relates to improvements in paper cutters and, more particularly, to a paper cutter of the type having a rotary blade.

In a conventional rotary blade cutter, a rotary cutter blade is moved along one side margin of a paper-supporting board and the blade is caused to rotate so as to cut the paper disposed in advance thereof. The means for rotating the blade has generally been comprised of a rack and pinion assembly wherein the pinion is coupled to the cutter blade and is enmeshed with a longitudinally extending rack, whereby rotation of the blade is effected due to the movement of the pinion along the rack.

While the foregoing means of rotating the blade have been found satisfactory, a problem which always exists in the use of such means is the friction encountered between the rack and the pinion. Such friction increases the effort needed to move the cutter blade to cut the paper and it is desirable to minimize such effort while assuring that the rotary cutter blade rotates at all times while it moves relative to the board.

The present invention provides an improvement over conventional rotary paper cutters of the type described by providing an improved means for mounting the cutter blade for rota tional movement as it is manually moved in a given direction to cut paper in advance thereof. Such improved means includes roller structure coupled to the cutter blade and resilient strap means coupled to the roller structure for rotating the same while providing an almost frictionless mounting for the roller structure to minimize the effort required to move the roller structure and thereby the cutter blade while assuring that the cutter blade rotates at all times as it cuts paper in ad vance thereof. To this end, the strap means comprises a resilient strap of a suitable material, such as spring steel or the like, which is partially wrapped around a pair of rollers defining the roller structure so that, when the rollers are moved over a predetermined path, the strap will quickly and easily conform to the rollers as they change position along the path yet the strap will engage the outer periphery of the rollers in a manner to cause rotation of the same and thereby cause rotation of the cutter blade connected to one of the rollers. In this way, the cutter blade can be moved quickly and easily through the paper in advance thereof so as to quickly and cleanly cut the paper.

The primary object of this invention is to provide improve ments in rotary paper cutters wherein the effort required to move the rotary paper cutter will be significantly reduced with respect to the effort required to move the rotary cutter blades of conventional paper cutters.

Another object of this invention is to provide an improved paper cutter of the rotary cutter type wherein resilient strap means is used to mount and to position roller structure coupled to a rotary cutter blade so as to minimize friction between the strap means and the roller structure and thereby reduce the effort required to move the rotary cutter through paper in advance thereof.

A further object of this invention is to provide a paper cutter of the type described which includes a pair of adjacent rollers confined in a channel member and having a resilient strap partially wrapped about the peripheries of the rollers when the ends of the strap are secured to respective ends of the channel member so that the rollers will rotate under the influence of the strap means as the rollers are moved longitudinally of the channel member yet the strap means will quickly and easily conform to the rollers to thereby minimize the frictional force therebetween for substantially all positions of the rollers along the channel member.

Other objects of this invention will become apparent as the following specification progresses, reference being hade to the accompanying drawing for an illustration of the invention.

In the drawings:

FIG. I is a perspective view of a rotary paper cutter utilizing the improvements of the present invention;

FIG. 2 is an enlarged, fragmentary, side elevational view, partly in section, of the paper cutter;

FIG. 3 is a fragmentary, cross-sectional view of the paper cutter showing the mounting means for the rotary cutter blade thereof; and

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 2.

The rotary paper cutter of the present invention is broadly denoted by the numeral and includes a cutter board 12, a rotary cutter blade 14 (FIG. 3), a mount 16 for mounting blade 14 for rotation, and a channel member 18 attached to board 12 for securing mount llb thereof for movement relative to the board adjacent to and along one side margin thereof. Board 12 has lines 20 formed therein to define a grid for use in properly positioning paper to be cut to a predetemiined size. The grid can have scale markings thereon, if desired. A guide plate 22 is secured to the upper surface: of board 12 and has an end face 24 which serves as a stop for paper supported on the board.

Channel member 18 is transversely C-shaped as shown in FIG. 3 and has a length which is substantially equal to the length of the adjacent side margin of board 12 in a manner such that channel member 18 is spaced outwardly of the board and slightly above the upper surface thereof as shown in FIG. 3. The board may be of wood so that brackets 26 can be secured thereto by screws or the like.

Mount 16 includes a pair of closely adjacent rollers 28 and 30 which are disposed within member 18 for rolling movement therewithin. The rollers are inserted in the channel member at one end thereof before the corresponding bracket 26 is secured to the channel member.

Roller 28 has a cylindrical extension 32 which is axially disposed thereon and which is positioned in the entrance of channel member 18 as shown in FIG. 3. Roller 28 and exten sion 32 present a bore for receiving a sleeve 34 of suitable material, such as steel or the like. Sleeve 34 is adapted to receive a square shaft 36 secured to rotary cutter blade 14. A coil spring 38 is received within the bore of roller 28 and etc tension 32 prior to insertion of shaft 36 therein, whereby the shaft, when the spring is compressed thereby, is biased in a direction out of the bore or to the left when viewing FIG. 3. A set screw 40 threadably couples extension 32 to sleeve 34, whereby the sleeve and thereby shaft 36 rotate with roller 28.

A tubular bearing member 42 is mounted on sleeve 34 and supports the same in an opening in a pllatelike extension 44 of handle 46 forming a part of mount 16. The handle also has a back plate 48 which, with extension 44, defines a space 50 for receiving channel member T8 in the manner shown in FIG. 3. A cover plate 52 is secured in any suitable manner to handle 46, such as by screws or the like, to conceal rotary cutter blade l4 as well as to prevent injury to the hand when mount l6 is secured to channel member 18.

Roller 30 is rotatably mounted on a roller bearing having a central opening into which is press-fitted a shaft 31 mounted in cantilever fashion on extension 44 in any suitable manner, such as by a screw or the like. Thus, roller 30 can rotate relative to channel member T8 and roller 28.

An elongated flexible strap 54 of spring material, such as spring steel or the like, is coupled to rollers 28 and 30 and to channel member 18 for causing rotation of blade 14 when mount 16 is manually moved along the length of the channel member. To this end, strap 54 is secured at one of its ends to the upper crosspiece 56 at one end of member 18 by a screw 58 or the like. The opposite end of strap 54 is secured in like manner to lower crosspiece 60 at the opposite end of member 18. The strap, extending from screw 58 (FIG. 2), extends along the inner surface of crosspiece 56 partially about roller 30 to form a first loop 62, then over and around roller 28 to form a second loop 64. The strap then extends beneath rollers 28 and 30 to the opposite end of channel member 18.

The resilient strap and roller arrangement provides a mounting for the rotary cutter blade which permits movement of mount 16 with minimum resistance: due to friction. This is achieved because the strap, when wrapped about the rollers, provides a support therefor which quickly and easily conforms to the rollers as they change position along the length of the channel member. This is due to the inherent resilience of the strap and because the strap snugly positions the rollers within the confines of crosspieces 56 and 60 of the channel member. Mount 16, therefore, provides an improvement for rotary cutter which permits paper to be quickly and easily cut with a minimum of effort in moving mount 16 along channel member 18.

To prevent rocking of mount 16 relative to channel member 18, an idler pulley 47 is provided, pulley 47 having a shaft 49 carried by extension 44 as shown in FIG. 4, pulley 47 being rotatably mounted on the shaft and in engagement with the underside of strap 54. Pulley 47 is also in proximity to second loop 64 as shown in FIG. 2.

The purpose of pulley 47 is to prevent rocking of mount 16 about the axis of shaft 36 in a clockwise sense when viewing FIG. 2. Similarly, pulley 30 prevents any substantial rocking movement of mount 16 in a counterclockwise sense when viewing FIG. 2.

If mount 16 were allowed to rock about shaft 36, rollers 28 and 30 would be forced into frictional engagement with strap 54 in a manner which would inhibit free movement of the mount along channel member 18. Using pulley 47, this problem does not arise and the mount is free to move at all times without rocking movement relative to channel member 18.

An elongated rigid member 66 of mild steel or the like is provided on the side of board 12 adjacent to channel member 18. Member 66 presents a cutting edge along which blade 14 moves. Member 66 has a rectangular cross section as shown in FIG. 3 wherein the four longitudinal edges of the member are sharply defined. Thus, each of these edges can be used as the cutting edge for the paper cutter and, if desired, member 66 can be reversed so that another edge is adjacent to the path of rotary blade 14.

In use, board 12 is assembled with channel member 18 mounted on one side extremity of bard l2 and mount 16 secured to the channel member for movement longitudinally thereof. When properly positioned, rotary cutter blade 14 will have a peripheral portion in engagement with the upper part of the side face 66 (FIG. 3) of member 65 and the blade will be biased against this side face by the action of spring 38. One or more sheets of paper can then be placed on the upper surface of board 12 with one edge of the paper in engagement with end face 24 of plate 22 and with a portion of the paper extending across the path of travel of the blade. Mount 16 will initially be adjacent to the end of channel member 18 near plate 22. Mount 16 is then moved toward the opposite end of the channel member and, in so doing, will cause blade 14 to cut the paper. The blade will rotate during the cutting action because of the rolling action of roller 28. After one sweep of the blade along the channel member, member 16 is then ready for another cutting operation since the blade can be moved in either direction for cutting paper.

lclaim:

l. A rotary paper cutter comprising: a board adapted to support a paper sheet to be cut; a rotary cutter blade for cutting the paper; and means mounting the cutter blade on the board for movement along a predetermined path adjacent to one side margin thereof, said mounting means including a pair of rollers, one of the rollers being coupled to the blade; a resilient strap for causing the rotation of the rollers and thereby the cutter blade as the rollers are moved relative to the board along said side margin thereof; and means securing each end of the strap, respectively, near a corresponding end of said path, said strap extending in one direction from one end of said path, then partially about a first of said rollers and in the opposite direction, then partially about the second roller and toward the other end of said path.

2. Paper cutting apparatus as set forth in claim 1, wherein is included a channel member mounted in a fixed position adjacent to said side margin of the board, said channel member having a pair of opposed crosspieces, said rollers being between the crosspieces, the securing means for one end of the strap being connected to one of the crosspieces near one end of the channel member and the securing means for the other end of the strap being connected to the other crosspiece near the opposite end of the channel member, said crosspieces providing backing supports for adjacent portions of said strap.

3. Paper cutting apparatus as set forth in claim 1, wherein is included an elongated channel member secured to the board and extending longitudinally of said one side margin thereof, said rollers being movable longitudinally of the channel member, and said mounting means further including a third roller adjacent to one of the rollers for holding said pair of rollers against rocking movement with respect to said channel member.

4. Paper cutting apparatus comprising: a board for supporting a paper sheet to be cut, said board having a side margin; a channel member; means mounting the channel member on the board adjacent to and extending along said side margin thereof, said channel member having upper and lower crosspieces; a handle having a pair of opposed plates in straddling relationship to the channel member, said plates defining a space therebetween, the channel member being disposed in said space; a pair of rollers; means mounting the rollers on one of said plates for rotation relative thereto with the rollers extending into the channel member, said plates defining a space therebetween, the channel member being disposed in said space; a pair of rollers; means mounting the rollers on one of said plates for rotation relative thereto with the rollers extending into the channel member and disposed between the crosspieces thereof; a rotary cutter blade; means mounting the cutter blade on one of the rollers for rotation therewith; and a resilient strap connected at one end thereof to said channel member near one of the crosspieces and connected at the opposite end thereof to the channel member near the other crosspiece, said strap extending parallel to and contiguous with said crosspieces as the rollers move in opposite directions in the channel member, whereby the strap causes the rollers to rotate when the handle is moved relative to the channel member.

5. In a rotary paper cutter of the type having a rotary blade movable along one side margin of a board, the improvement comprising: a pair of rollers; means adapted to be secured to the board for mounting the rollers for movement along said one side margin thereof, one of the rollers adapted to be coupled to the blade for rotating the latter as it moves relative to the board, said mounting means including a pair of spaced surfaces, said rollers being between said surfaces; and a resilient strap partially wrapped about the rollers and normally extending along and being contiguous to said surfaces.

6. Apparatus as set forth in claim 5, wherein said one roller has a bore therein for receiving the shaft of the rotary blade, and including a spring in the bore for biasing the shaft out of the same.

7. Apparatus as set forth in claim 5, wherein said mounting means comprises a channel member have a transversely C- shaped configuration, said rollers being disposed in the channel member for movement longitudinally thereof.

8. Apparatus as set forth in claim 5, wherein is included a third roller adjacent to one of said pair of rollers for holding said pair of rollers against rocking movement relative to said board.

9. Paper cutting apparatus comprising: a board for supporting a paper sheet to be cut, said board having a side margin; a channel member; means mounting the channel member on the board adjacent to and extending along said side margin thereof, said channel member having upper and lower crosspieces; a handle having a pair of opposed plates in straddling relationship to the channel member, said plates defining a space therebetween, the channel member being disposed in said space; a pair of rollers; means mounting the rollers on one of said plates for rotation relative thereto with the rollers ex tending into the channel member and disposed between the crosspieces thereof; a rotary cutter blade; means mounting the cutter blade on one of the rollers for rotation therewith; and a resilient strap extending along the upper crosspiece of the channel member from one end thereof, across said rollers, about an arcuate portion of one of the rollers and beneath the latter, about an arcuate portion of the other roller and over the latter, and along the lower crosspiece to the opposite end 5 of the channel member, the ends of the strap being secured to respective ends of the channel member. 

1. A rotary paper cutter comprising: a board adapted to support a paper sheet to be cut; a rotary cutter blade for cutting the paper; and means mounting the cutter blade on the board for movement along a predetermined path adjacent to one side margin thereof, said mounting means including a pair of rollers, one of the rollers being coupled to the blade; a resilient strap for causing the rotation of the rollers and thereby the cutter blade as the rollers are moved relative to the board along said side margin thereof; and means securing each end of the strap, respectively, near a corresponding end of said path, said strap extending in one direction from one end of said path, then partially about a first of said rollers and in the opposite direction, then partially about the second roller and toward the other end of said path.
 2. Paper cutting apparatus as set forth in claim 1, wherein is included a channel member mounted in a fixed position adjacent to said side margin of the board, said channel member having a pair of opposed crosspieces, said rollers being between the crosspieces, the securing means for one end of the strap being connected to one of the crosspieces near one end of the channel member and the securing means for the other end of the strap being connected to the other crosspiece near the opposite end of the channel member, said crosspieces providing backing supports for adjacent portions of said strap.
 3. Paper cutting apparatus as set forth in claim 1, wherein is included an elongated channel member secured to the board and extending longitudinally of said one side margin thereof, said rollers being movable longitudinally of the channel member, and said mounting means further including a third roller adjacent to one of the rollers for holding said pair of rollers against rocking movement with respect to said channel member.
 4. Paper cutting apparatus comprising: a board for supporting a paper sheet to be cut, said board having a side margin; a channel member; means mounting the channel member on the board adjacent to and extending along said side margin thereof, said channel member having upper and lower crosspieces; a handle having a pair of opposed plates in straddling relationship to the channel member, said plates defining a space therebetween, the channel member being disposed in said space; a pair of rollers; means mounting the rollers on one of said plates for rotation relative thereto with the rollers extending into the channel member, said plates defining a space therebetween, the channel member being disposed in said space; a pair of rollers; means mounting the rollers on one of said plates for rotation relative thereto with the rollers extending into the channel member and disposed between the crosspieces thereof; a rotary cutter blade; means mounting the cutter blade on one of the rollers for rotation therewith; and a resilient strap connected at one end thereof to said channel member near one of the crosspieces and connected at the opposite end thereof to the channel member near the other crosspiece, said strap extending parallel to and contiguous with said crosspieces as the rollers move in opposite directions in the channel member, whereby the strap causes the rollers to rotate when the handle is moved relative to the channel member.
 5. In a rotary paper cutter of the type having a rotary blade movable along one side margin of a board, the improvement comprising: a pair of rollers; means adapted to be secured to the board for mounting the rOllers for movement along said one side margin thereof, one of the rollers adapted to be coupled to the blade for rotating the latter as it moves relative to the board, said mounting means including a pair of spaced surfaces, said rollers being between said surfaces; and a resilient strap partially wrapped about the rollers and normally extending along and being contiguous to said surfaces.
 6. Apparatus as set forth in claim 5, wherein said one roller has a bore therein for receiving the shaft of the rotary blade, and including a spring in the bore for biasing the shaft out of the same.
 7. Apparatus as set forth in claim 5, wherein said mounting means comprises a channel member have a transversely C-shaped configuration, said rollers being disposed in the channel member for movement longitudinally thereof.
 8. Apparatus as set forth in claim 5, wherein is included a third roller adjacent to one of said pair of rollers for holding said pair of rollers against rocking movement relative to said board.
 9. Paper cutting apparatus comprising: a board for supporting a paper sheet to be cut, said board having a side margin; a channel member; means mounting the channel member on the board adjacent to and extending along said side margin thereof, said channel member having upper and lower crosspieces; a handle having a pair of opposed plates in straddling relationship to the channel member, said plates defining a space therebetween, the channel member being disposed in said space; a pair of rollers; means mounting the rollers on one of said plates for rotation relative thereto with the rollers extending into the channel member and disposed between the crosspieces thereof; a rotary cutter blade; means mounting the cutter blade on one of the rollers for rotation therewith; and a resilient strap extending along the upper crosspiece of the channel member from one end thereof, across said rollers, about an arcuate portion of one of the rollers and beneath the latter, about an arcuate portion of the other roller and over the latter, and along the lower crosspiece to the opposite end of the channel member, the ends of the strap being secured to respective ends of the channel member. 